A new gun law proponents say helps law enforcement has driven Smith & Wesson and Sturm Ruger out of California, and affirmed the suspicions of firearms rights advocates that the measure is really about making handguns obsolete.

The two companies have announced they will stop selling their wares in the nation’s most populous state rather than try to comply with a law that requires some handguns to have technology that imprints a tiny stamp on the bullet so it can be traced back to the gun. The companies, and many gun enthusiasts, say so-called “microstamping” technology is unworkable in its present form and can actually impair a gun’s performance.

“Smith & Wesson does not and will not include microstamping in its firearms,” the Springfield, Mass.,-based manufacturer said in a statement. “A number of studies have indicated that microstamping is unreliable, serves no safety purpose, is cost prohibitive and, most importantly, is not proven to aid in preventing or solving crimes.”